The present invention relates generally an electronic component cooling system. More specifically, the present invention relates to a cooling system for electronic power and/or control components of an air-cooled chiller system.
Electrical components associated with the electronic powering of a chiller system generate a great deal of heat in operation. Since these components are typically housed in a compact enclosure that is substantially sealed against exposure to the elements, the heat generated within the enclosure by the power electronic components must be dissipated to avoid damaging the components. Power electronic semi-conductor components in the enclosure that generate especially large amounts of heat during operation are typically cooled using a chill plate. The chill plate is composed of a material having high thermal conductivity and includes internal channels, which constitute a portion of a heat transfer fluid loop that circulates a working fluid or refrigerant fluid to cool the electrical components. The working fluid that flows through the heat transfer fluid loop is placed in a heat exchange relationship with the chill plate channels to remove thermal energy from the chill plate. The heat transfer fluid loop can be part of a separate cooling system for the enclosure to dissipate the thermal energy from the chill plate. The heat transfer fluid loop can also be incorporated into the chiller system as part of the refrigeration loop or as part of a condenser fluid loop. The electrical components are mounted on the exterior of the chill plate, with the chill plate drawing thermal energy from the electrical components by thermal conduction. Thermal energy transferred to the chill plate is then transferred by convection to the working fluid that flows in the channels of the fluid loop.
Other electrical components housed in the enclosure generate a reduced amount of thermal energy in operation such that a chill plate is not required. For these components, an additional heat transfer fluid loop, similar to that as described above, extends into the substantially closed space of the enclosure in combination with a fan operating inside the enclosure to circulate air inside the enclosure for achieving heat dissipation. However, condensation may form inside the enclosure when the temperature of the working fluid in the heat transfer fluid loop is less than the dew point temperature inside the cabinet. Condensation is undesirable, as it can damage the electrical components. To prevent the formation of condensation, a separate temperature monitoring and control system is then required that prevents the inside temperature of the enclosure from reaching a level that is less than the dew point temperature.
Therefore, what is needed is a cooling system for the electrical components situated in an electrical enclosure of a chiller system that can substantially prevent the formation of condensation in the enclosure without requiring a separate temperature monitoring and control system.